Biomedical subjects

R Sakata

Publications and source records attributed to R Sakata.

At least 55 records · Page 3Linked to original sources

PubMed2000

Analysis by early angiography of right internal thoracic artery grafting via the transverse sinus : predictors of graft failure.

BACKGROUND: There has been debate regarding whether technically demanding right internal thoracic artery (RITA) grafting via the transverse sinus can be extensively applied to patients in high-risk groups, such as patients with a small body size, elderly patients, and woman with relatively smaller coronary artery and internal thoracic artery (ITA) diameters. METHODS AND RESULTS: Of the 1456 patients who underwent isolated coronary artery bypass grafting between January 1989 and December 1998 at Kumamoto Central Hospital, 393 patients (mean age, 62.4+/-9.0 years) with the RITA anastomosed to the major branches of the circumflex artery were studied. Left ITA grafting was performed in 384 patients, and in 369, the in situ left ITA was anastomosed to the left anterior descending coronary artery using standard methods. Early postoperative angiography was performed in 381 patients. The RITA was occluded in 4 patients, and string-like artery and significant stenosis were present in 11 and 7 patients, respectively; RITA graft patency was thus 94.1%. Of the preoperative variables and angiographic data, simple and multiple logistic regression analyses identified decreased severity of native stenosis, diffuse sclerosis of native vessels, and residual side branches of the ITA as independent predictors of nonfunctional grafts. The method of ITA grafting did not influence the patency of the graft. CONCLUSIONS: The excellent patency rate demonstrated by this study, the largest angiographic study to date of RITA grafting via the transverse sinus, indicates that this technique can provide reliable revascularization of the left ventricle and that it has the potential to be applied to a wide variety of patients with diseased circumflex arteries.

Adolescent↗

PubMed2000

Long-term results of root reconstruction using the Carrel patch.

OBJECTIVE: The treatment of annuloaortic ectasia in patients, including those with Marfan syndrome, ascending aortic dissection, and other disorders of the ascending aorta and aortic valve presents a surgical challenge that has, unfortunately, shown high hospital mortality up to now. Improvements in graft materials and advanced surgical techniques have, however, begun to reduce hospital mortality. SUBJECTS AND METHODS: We retrospectively analyzed the records of 47 consecutive patients who undergoing aortic root reconstruction using the Carrel patch between January 1991 and March 1999. RESULTS: Postoperative complications included myonephrotic metabolic syndrome caused by femoral artery cannulation in 2 patients. Reexploration was done to halt bleeding in 2 patients. In 1 of 4 acute dissection patients, retrograde filling of the false lumen was demonstrated postoperatively. Overall surgical mortality in this series was 2.1% (1 of 47). The cardiac-event free rate was 98% at 5 years and 88% at 8 years. Actual survival is 97.8% at 8 years. No anastomosis complications were seen during follow-up (average: 32.7 months) (about 2.73 years). CONCLUSION: Surgery is considered feasible in any anatomic variation of aortic root disease, even in coronary ostial minimal dislocation, and the Carrel patch holds hope in preventing of anastomotic pseudaneurysm and ensuring long-term survival. Our experience suggests that modified Bentall operation, or aortic root remodeling using the Carrel patch, has few late-term complications, even in Marfan patients.

Adult↗

PubMed2000

Complete revascularization of the left anterior descending coronary artery.

OBJECTIVE: To assess the efficacy of complete revascularization of the left anterior descending coronary artery. METHODS: To obtain such revascularization, 81 patients required the use of such complex techniques as the onlay patch technique or double bypasses during bypass grafting. RESULTS: The onlay patch technique was used in 39 (48%) and double bypasses in 42 (52%). The wall motion in all anterior segments of the left ventricle showed an improving trend postoperatively. The patency rate was 99% overall, and the bypass grafts to the left anterior descending coronary artery were all patent with flow in all left anterior descending coronary artery areas. Perioperative myocardial infarction occurred in only 1 patient (1.2%), and hospital mortality was 2.5% (2/81). Long-term results of 79 hospital survivors were as follows: the mean follow-up time was 77 months (3 to 236); the actuarial survival rate including all deaths and estimated by cardiac death was 90% and 95% at the eighth postoperative year respectively; the cardiac event free rate at the fifth and eighth postoperative year was 90% and 63% respectively. A total of 8 cardiac events were observed. Excluding 3 cardiac deaths, no cardiac events were clearly attributable to the left anterior descending coronary artery. CONCLUSIONS: Complete revascularization of the left anterior descending coronary artery using these techniques improved the anterior wall motion in the left ventricle and cardiac performance at low risk, and provided excellent long-term results.

Adult↗

PubMed2000

Long-term results of bilateral internal thoracic artery grafting.

BACKGROUND: Little is known about the long-term results of the uniform group of patients who had bilateral internal thoracic artery (ITA) grafting with the method of left ITA-to-left anterior descending coronary artery and right ITA-to-circumflex artery. METHODS: Late follow-up study was performed in the first consecutive 203 patients (mean age, 62.6 +/- 9.1 years) who underwent isolated coronary artery bypass grafting with the left ITA anastomosed to the left anterior descending coronary artery and the right ITA to major branches of the circumflex artery. The patients were grouped according to the patency of ITA grafts demonstrated by early postoperative angiography (Both patent (BP) group, 168 patients: both ITAs showed complete patency; Not patent (NP) group, 23 patients: at least one ITA was dysfunctional). RESULTS: Actuarial 7-year survival in all patients was 89.3% +/- 3.1%. The cumulative probability of event-free survival for cardiac death, myocardial infarction, intervention, and angina at 7 years was 96.6% +/- 1.8%, 98.0% +/- 1.5%, 86.7% +/- 3.2%, and 90.7% +/- 2.9%, respectively. NP group had more myocardial infarction and angina than the BP group, but was not statistically significant. Because of failed grafts at the early angiography, intervention was performed more frequently in NP group (p < 0.01). CONCLUSIONS: Our results of actuarial 7-year survival and the cumulative probability of event-free survival were at least comparable to the results of other similar studies using bilateral ITA. The freedom from angina appeared to be better than in the previous study. Overall our study supports the continued use of this method of ITA grafting.

Adolescent↗

PubMed2000

Craniocervical and aortic atherosclerosis as neurologic risk factors in coronary surgery.

BACKGROUND: Advanced age is associated with increased systemic atherosclerosis and is a consistent neurologic risk factor after coronary artery bypass grafting (CABG). METHODS: We studied prospectively whether varying degrees of a total atherosclerotic score derived from the brain, carotid arteries, and ascending aorta predicted postoperative neuropsychologic (NP) dysfunction and stroke in 177 elderly patients (> or = 60 years) undergoing CABG. RESULTS: Group L (low total atherosclerotic score) had rates of NP dysfunction of 25% and 4%, group I (intermediate) had rates of 33% and 22%, and group H (high) had rates of 79% and 43% on postoperative days 1 and 7, respectively (p < 0.001). The incidence of stroke was higher in group H (14.3%) than in groups I and L (7.8% and 0.9%; p = 0.013). Stepwise logistic regression analysis demonstrated the significant predictors of NP dysfunction on postoperative day 7 to be total atherosclerotic score, peripheral vascular disease, and diabetes mellitus, and those of stroke to be total atherosclerotic score, peripheral vascular disease, and hyperlipidemia. CONCLUSIONS: Perioperative evaluation of craniocervical and aortic atherosclerosis is useful to identify a high-risk patient at postoperative NP dysfunction and stroke after CABG.

Aged↗

PubMed2000

Ultrasonographic demonstration of manipulation-related aortic injuries after cardiac surgery.

OBJECTIVES: This study was performed to evaluate the frequency and risk factors associated with new aortal lesions induced by surgical manipulation and their correlation with postoperative stroke. BACKGROUND: Little is known about the causative mechanism of intraoperative atheroembolism after cardiac surgery. METHODS: Epiaortic echocardiography was performed before cannulation and after decannulation in 472 patients undergoing cardiac surgery with extracorporeal circulation. RESULTS: A new lesion in the ascending aortal intima was identified in 16 patients (3.4%) after decannulation. New lesions were severe, with mobile lesions or disruption of the intima in 10 patients. Six of the severe lesions were related to aortic damping and the other four to aortic cannulation. Three patients in this group had postoperative stroke. Univariate analysis identified only the maximal thickness of the atheroma near the aorta manipulation site as a predictor of new lesions. The incidence of new lesions was 11.8% if the atheroma was approximately 3 to 4 mm thick and as high as 33.3% if the atheroma was >4 mm, but only 0.8% when it was <3 mm. Total 10 patients (2.1%) sustained neurological complications. Arteriosclerosis obliterans, atherosclerosis of the aorta and new mobile lesions were identified as predictors of strokes. CONCLUSIONS: This study demonstrated an association between new lesions created by surgical maneuvers and postoperative stroke. Embolic strokes were more likely to occur if new lesions were complicated with intimal disruption, especially of the mobile type. Modifications in surgical procedures will be needed if thick plaque (especially >4 mm) is noted near the manipulation site.

Adult↗

PubMed2000

Inhibition of transforming growth factor beta prevents progression of liver fibrosis and enhances hepatocyte regeneration in dimethylnitrosamine-treated rats.

We investigated whether anti-transforming growth factor beta (TGF-beta) molecular intervention can halt the progression of liver fibrosis in rats. To block TGF-beta action in a specific manner, we prepared an adenovirus expressing a truncated type II TGF-beta receptor (AdTbeta-TR), which specifically inhibits TGF-beta signaling as a dominant-negative receptor. We also used an adenovirus expressing bacterial beta-galactosidase (AdLacZ) as a control adenovirus. Rats were treated with dimethylnitrosamine (DMN) for 3 weeks; then, AdTbeta-TR, AdLacZ, or saline was intravenously applied once, followed by an additional 3-week DMN treatment. The ratio between the truncated receptor and the wild-type receptor at the mRNA level was 15 at 1 week and 10 at 3 weeks after gene transfer. Immunohistostaining analysis showed that the truncated receptor was expressed mainly in septal cells including hepatic stellate cells. Liver fibrosis, as assessed by histology, hydroxyproline content, and the serum level of hyaluronic acid, progressed during the additional 3-week DMN treatment. However, in rats infected with AdTbeta-TR, the fibrosis remained at the level seen in rats given DMN for only 3 weeks. All AdTbeta-TR-treated rats remained alive, whereas DMN-treated rats infused with either AdLacZ or saline died of liver dysfunction. In the livers of AdTbeta-TR-treated rats, electron microscopy showed: 1) less accumulation of extracellular matrix proteins in the Disse's spaces; 2) regenerated hepatocytes; and 3) fat droplet-rich "quiescent" hepatic stellate cells. Our results demonstrate that TGF-beta plays a critical role in the progression of liver fibrosis, and suggest that anti-TGF-beta intervention should be therapeutic in already-established fibrotic livers, not only by suppressing fibrosis, but by facilitating hepatocyte regeneration.

Animals↗

PubMed2000

Echocardiographic and pathological evaluation of atherosclerosis in the ascending aorta during coronary artery bypass grafting.

UNLABELLED: We performed intraoperative echocardiography with an epiaortic probe to assess the correlation between echocardiographic appearance and pathological findings of the aorta and to examine the effect of cross-clamping on the aortic wall in 276 patients who underwent coronary artery bypass grafting. The ascending aorta was divided into three segments as follows: lower (L), upper (U), and innominate. The anterior (ant) and posterior (post) intimal thicknesses of each of the three segments were measured. The echogenicity at each of the six locations was examined and was classified as isoechoic or nonisoechoic (hyperechoic, hypoechoic, or mixed type). Tissue punched from the ant L wall of the ascending aorta for vein anastomosis was examined for the presence of atheroma. At the ant L, the prevalence of atheroma was significantly higher in nonisoechoic walls than in isoechoic walls (P = 0.049). We divided patients into two groups according to echogenicity at the U segments. Group A (n = 213) consisted of patients whose echogenicities at both ant U and post U were isoechoic. Group B (n = 63) consisted of patients with nonisoechoic echogenicity at ant U and/or post U. The intimal thicknesses at all six locations in Group B patients were greater than those of Group A (P < 0.01). Deformities at the clamp site after cardiopulmonary bypass were observed significantly more often in Group B than in Group A (P < 0.01). Our data suggest that a nonisoechoic aortic wall indicates more advanced atheroma and a higher risk of deformities at the clamp site. Examination of the echogenicity of the ascending aorta may be one method to reduce perioperative neurological complications. IMPLICATIONS: We performed epiaortic echocardiography during coronary artery bypass grafting and found that the presence of atheroma and deformities at the cross-clamping site were significantly more prevalent in nonisoechoic walls than isoechoic walls.

Aged↗

PubMed2000

Necessity of monitoring HPLC by a X-R control chart on measurement of serum fat-soluble vitamins.

In epidemiologic studies, many serum samples obtained from a large population have to be processed for measurement of fat-soluble vitamins. Quantification results by a high performance liquid chromatography (HPLC) should be stable in both intra- and inter-run, and a quality control may be performed by a X-R control chart. The present study shows that serum retinol, alpha-tocopherol, alpha-carotene, beta-carotene, and lycopene could be measured simultaneously, by 1) use of photodiode-array (POD) detector, 2) selection of some optimal analytical conditions (e.g. column, mobile phase, column temperature), 3) applying 2 internal standards, and 4) monitoring by a X-R control chart. The present procedure yielded relatively low coefficients of variations (CVs) compared to some reported figures. However, determination of CVs only does not ensure the accuracy and precision of an assay system, and application of a X-R control chart may be necessary for a good quality control of measurement, such as serum fat-soluble vitamins.

Chromatography, High Pressure Liquid↗

PubMed2000

Cardiac operations in patients with severe pulmonary impairment.

Many reviews concerning pulmonary complications after cardiac surgical procedures in patients with serious pulmonary disease have been published. However, no strict pulmonary function guidelines were proposed to help the clinician identify the patients at greater risk. We considered whether a low pulmonary function became a risk factor of cardiac operations. We conducted a retrospective analysis of records of 32 patients with severely impaired preoperative pulmonary function who had undergone cardiac operations between July 1988 and March 1999. There was 1 hospital death. The over-all mortality rate was 3.1% (1 of 32). However, this death could not be directly attributed to postoperative pulmonary complications. Postoperative pulmonary complications were seen in 2 patients (6.3%) who required tracheostomy due to atelectasis and pneumonia. No late deaths due to pulmonary complications were observed during the follow-up period. The actual survival rate is 68% at 7 years. A low pulmonary function did not, by itself, become a risk factor of cardiac operations, although a pulmonary function test can be used to alert the clinician to possible postoperative complications, including the requirement of tracheostomy. Especially strict control of postoperative respiration is necessary in patients with forced expiratory volume (FEV) of 1.0 <= 800 ml and/or FEV1.0/BSA <= 600 ml/m2.

Aged↗

PubMed2000

[Surgical results of valvular heart disease combined with myocardial revascularization].

Risk factors for hospital death after combined valvular and coronary artery bypass surgery were examined in 131 consecutive cases between October 1988 and December 1999. These accounted for 8.0% of all 1,644 cases of coronary revascularization surgery and 15.3% of all 854 cases of valvular heart disease surgery. 84 men and 43 women underwent combined valvular and coronary artery bypass surgery. The mean age of the patients was 68.9 +/- 3.9 (22-86) years old. Numbers of cases comprised 58 undergoing aortic valve surgery, 63 undergoing mitral valve surgery, and 10 undergoing eight patients died during hospitalization after the operation: four due to cardiac death and four due to non-cardiac death. We studied pre- and perioperative risk factors for hospital death by means of multivariate analysis. As the major factors, ischemic mitral regurgitation, chronic renal failure, and duration of cardiopulmonary bypass were identified as three major predictors of hospital death. Ischemic mitral regurgitation was the strong predictor (p = 0.03) with 5 hospital deaths out of 38 ischemic mitral regurgitation cases (13.1%), whereas only 3 hospital deaths were seen in 93 other cases (3.2%) operated on in the same period. Over all operation results were not unfavorable, indicating that combined operations may be electively performed if severe coronary artery disease was present. The surgical results with ischemic mitral regurgitation are as yet not well documented and will require further study.

Adult↗

PubMed2000

[Perioperative risk factors in valve surgery concomitant with coronary artery bypass grafting].

Between January 1990 and December 1999, 20 patients underwent the valve surgery concomitant with coronary artery bypass grafting. There were 16 males and 4 females, their mean age was 66.5 years. Of the 20 patients, aortic stenosis was noted in 7, aortic regurgitation in 3, mitral stenosis in one, and mitral regurgitation in 9 patients. The cause of mitral regurgitation was considered to be an ischemic change in six patients, including ruptured papillary muscle due to myocardial infarction in two patients. On the contrary, LMT lesion was recognized in 5, LAD lesion in 17, LCX in 16, and RCA in 12 patients. Seven patients had preoperative myocardial infarction, three patients were required preoperative IABP support. AVR was performed in 10, MVR in 5, and MAP in 5 patients. The number of bypass was 1.9 +/- 0.85. Four patients died of LOS and MOF. The remaining 16 patients have been doing well. The significant difference between the survived and the not survived patients was recognized in the factor of emergency, preoperative IABP, papillary muscle rupture due to myocardial infarction, history of PTCA, LAD lesion, and the time of CPB. The factors regarding coronary artery had the influence on the outcome of a patients of valve surgery concomitant with CABG. Therefore, an appropriate myocardial protection and perioperative management for ischemia were mandatory.

Adult↗

PubMed2000

[Surgical treatment for malignant pleural mesothelioma in eight cases].

Between 1987 and March 2000, we have operated on eight patients for malignant mesothelioma which consisted of four of localized type and four of diffuse type. We have aggressively resected mesothelioma combined with chemotherapy whether the tumor was primary or recurrent, and concluded the following. 1) In localized malignant mesothelioma, en-bloc primary tumor resection was possible and additional resection for recurrence was effective and useful for long time survival. 2) In diffuse malignant mesothelioma, complete tumor resection was impossible to even perform pleuropneumonectomy accompanied with partial resection of pericardium and diaphragm and, therefore, the prognosis was poor in four patients and all died around one year. 3) Because recurrent pattern for localized type was diffuse type, diagnosis and surgical treatment in early stage was essential for long time survival.

Adult↗

PubMed2000

Long-term angiographic evaluation of free internal thoracic artery grafting for myocardial revascularization.

Between 1990 and 1998, 41 patients underwent free internal thoracic artery grafting for coronary artery bypass. To investigate usefulness of free internal thoracic artery grafting, we compared the postoperative graft patency of free internal thoracic artery grafts with that of in situ internal thoracic artery grafts, and compared the long-term results such as actual survival and cardiac-event free rate in patients receiving free internal thoracic artery grafts with those results in patients receiving in situ internal thoracic artery grafts. Postoperative changes in luminal diameter of free internal thoracic artery grafts were calculated as the difference between the first and secondary angiographic evaluation in 17 patients who were followed-up for more than 5 years. The early postoperative graft patency rate of free internal thoracic artery was 95.2%. All these early patent grafts remained patent at the time of the late study. At 9 years post-surgery, patients who received free internal thoracic artery grafts had a survival rate of 100% and a cardiac event-free rate of 77.5%; the luminal diameter enlargement was 0.57 mm, and the mean matching rate increased 27.8%. We conclude that the free internal thoracic artery provides long-term results comparable with those of in situ internal thoracic artery.

Aged↗

PubMed1999

Experimental spinal fusion using sintered bovine bone coated with type I collagen and recombinant human bone morphogenetic protein-2.

STUDY DESIGN: Posterolateral lumbar transverse process fusion using recombinant human bone morphogenetic protein (rhBMP)-2 carried by sintered bovine bone and Type I collagen complex was compared with fusion achieved using autogeneous bone graft or sintered bovine bone alone. OBJECTIVES: This study examined the efficacy of sintered bovine bone coated with Type I collagen as a carrier of rhBMP-2 for lumbar intertransverse process arthrodesis. SUMMARY OF BACKGROUND DATA: Posterolateral intertransverse process arthrodesis using osteoinductive growth factors is performed experimentally in the lumbar spine. The previous studies revealed the efficacy of osteoinductive factors applied to carriers having no bony structures, such as collagen sheet or polylactic acid polymer, for the spinal fusion. However, in their studies, a large amount of osteoinductive proteins have been applied for the spinal fusion. We used the sintered bovine bone "True Bone Ceramics" (TBC; Koken Co., Tokyo, Japan) coated with type I collagen as the carrier. True Bone Ceramics is the only biomaterial possessing a natural trabecular structure and an organized crystal of bone minerals. METHODS: Twenty-two adult rabbits underwent bilateral lumbar intertransverse process arthrodesis at L4-L5. The animals were divided into four groups and had materials implanted as follows: autologous bone group, grafted autologous corticocancellous bone harvested from the posterior iliac crest; implanted TBC group; TBC collagen group, implanted TBC coated with Type I collagen infiltrating into the porous space; and BMP group, implanted sintered bovine bone coated with Type I collagen infiltrated with 100 micrograms of rhBMP-2. Spinal fusion was evaluated by radiographic analysis, manual palpation, biomechanical testing, and histologic examination 6 weeks after surgery. RESULTS: Two rabbits were killed because of infection and lumbar plexus palsy. Radiographs of the BMP group showed a homogeneous fusion mass at the intertransverse area, and stability was confirmed by dynamic radiographs at 3 and 6 weeks after surgery. In the BMP group, a bony mass in the intertransverse area was more prominent than in the other groups. The BMP group had a higher fusion rate based on manual palpation than the-other groups, and BMP fusions showed significantly higher tensile strength and stiffer fusion. The histologic findings in the BMP group demonstrated membranous bone and endochondral bone formations between the transverse process and the fusion mass. In the other groups, continuous trabecular bone formation was observed in the area surrounding the transverse process, but gaps between grafted fragments and less mature bone formation were present in the intertransverse area. CONCLUSIONS: Sintered bovine bone coated with Type I collagen and rhBMP-2 resulted in a higher fusion rate than the autograft and can be used as a carrier for rhBMP-2 in spinal fusion.

Animals↗

PubMed1999

In situ right internal thoracic artery graft for revascularization of circumflex artery. Early results and long-term angiographic follow up.

In 285 patients, the right internal thoracic artery, routed through the transverse sinus, was in most cases anastomosed to the circumflex branches. In 278 cases, the left internal thoracic artery was simultaneously used for revascularization of the left anterior descending artery. Two patients died (mortality rate 0.7%). Postoperative early angiography on 278 patients revealed a high graft patency of 97.8% for the right internal thoracic artery and 96.9% for the left internal thoracic artery. A long-term follow-up study was performed on the first consecutive 115 patients who survived the operation. Seven patients died, 2 due to cardiac causes. Angiographic assessment was performed in 73 patients (67%) at an interval of 28.8 to 93.1 months (mean 58.9 months). Five right internal thoracic arteries were occluded and sledlike right internal thoracic artery grafts were present in 2 patients. Two of them had been confirmed in the previous early study to be not patent. Insufficient data was obtained in 4 patients. The perfect patency rate of the right internal thoracic artery was 89.9% (62/69). Five left internal thoracic arteries were occluded, providing a perfect patency rate of 92.3%. There was no significant difference between the success rate using the right internal thoracic artery and that resulting from using the left internal thoracic artery. We conclude that coronary revascularization using this technique provides good clinical results and excellent early and late patency of the right internal thoracic artery.

Adolescent↗

PubMed1999

Extracorporeal circulation before and after ultrasonographic evaluation of the ascending aorta.

BACKGROUND: To further gain insight into atheroembolization mechanisms epiaortic two-dimensional echocardiographic evaluation before extracorporeal circulation and after decannulation may be helpful. METHODS: Epiaortic two-dimensional echocardiography was performed before cannulation and after decannulation in 188 (124 men) patients (mean age, 67.7 years; range, 43 to 86 years) undergoing operation with extracorporeal circulation for ischemic heart disease during 1996. RESULTS: After decannulation, a new intimal lesion was recognized in 10 of 188 patients (5.3%): mobile type in 5 patients (3 ending with a stroke [60%], 2 having brain computed tomographic scans compatible with embolism), intimal tear in 2, and intimal irregularity in 3 patients. Stroke occurred in a significantly smaller number of patients (2 of 178 [1.1%]; p < 0.001) without new lesions. CONCLUSIONS: Clamp- or cannula-induced new lesions, especially of mobile type, are often complicated by postoperative stroke. Aggressive surgical technique modifications may need to be considered to avoid creating new lesions, particularly of the mobile type.

Adult↗

PubMed1999

Bileaflet mechanical valve (St. Jude Medical valve) replacement in long-term dialysis patients.

BACKGROUND: Few reports exist on the results of bileaflet mechanical valve (St. Jude Medical prosthesis; St. Jude Medical, Inc, St. Paul, MN) replacement in long-term dialysis patients. METHODS AND RESULTS: We retrospectively reviewed 12 patients, ranging in age from 50 to 86, undergoing long-term renal dialysis who had also undergone mechanical valve replacement at our institution. Operative procedures included aortic valve replacement, aortic and mitral valve replacement, aortic valve replacement and mitral annuloplasty, mitral valve replacement, and modified Bentall's operation. There was 1 hospital death (8.3%). During the mean follow-up period of 37.1 months (range: 5-87 months), there were 2 noncardiac late deaths. Bleeding from the esophageal varix and from a duodenal ulcer occurred in 1 patient with end-stage liver cirrhosis. There were no other major cases of bleeding or cerebrovascular accidents. There were no valve-related complications. All the survivors demonstrated excellent clinical improvement under the NYHA functional classification. CONCLUSIONS: Our study demonstrated good early and long-term results of mechanical valve replacement in patients undergoing long-term dialysis. These favorable results support the continued use of mechanical valves in dialysis patients.

Aged↗